Certain room temperature vulcanizing (R.T.V.) silicone rubbers are excellent mold making materials for the purpose of providing precise surface detail of an existing part or prototype. In addition to their excellent reproduction characteristics, R.T.V. silicones exhibit low shrinkage in a range from 0 to 0.006 inches per inch and elongation ranging from 100 to 1000 percent.
One of the major disadvantages of silicone rubber molds is their tendency to distort. This problem is overcome in the prior art by casting the silicone rubber in an enclosure especially fabricated to permit the silicone rubber to have a considerable thickness. This thickness may range from one inch to six inches depending on the size of the part. There is a limit however as to the thickness that a silicone rubber mold can be made because they become self-deforming due to their own weight.
Another disadvantage of R.T.V. silicone rubber mold is the high cost of the materials. One of the objects of this invention is to provide a mold material that has the advantages of a silicone rubber mold but is less expensive to make.
Another object of this invention is to provide a mold material that has more rigidity than a conventional silicone rubber mode.
A further object of this invention is to provide a mold material that is easier to handle than conventional silicone rubber molds.